Adjustable filter scraper blade



1954 J. w. LITTLE ADJUSTABLE FILTER SCRAPER BLADE Filed Nov. 29, 1951INVENTOR. JOHN W Ll TTLE Patented Feb. 16, 1954 ADJUSTABLE FILTERSCRAPER BLADE John W. Little, Birmingham,

Ala., assignor to Goslin-Birmingham Manufacturing Company, Inc., acorporation of Alabama Application November 29, 1951, Serial No. 258,836

Claims.

This invention relates to an adjustable scraper blade for rotary filtersand has for its principal object the provision of such a blade whichshall be easily adjusted to the exact pressure required from the outsideof the casing and while the filter is in operation.

Another object of my invention is to provide an adjustable scraper bladeof the character designated which may be easily adjusted to cause theblade to bear against the surface of the filter drum sufficiently toremove the cake formed thereon and yet not bear hard enough to damagethe filter cloth.

A more specific object of my invention is to provide an adjustablefilter scraper blade which is especially adapted for use on filtersemployed in the solvent de-waxing of oil.

A still further object of my invention is to provide an adjustablefilter scraper blade which shall be easily adjusted to bear against thesurface of the filter drum with substantially uniform pressure from endto end by a single operation, thus eliminating the necessity of havingto make several adjustments longitudinally of the blade every time theblade is adjusted.

Heretofore in the art to which my invention relates, the scraper bladeshave been adjusted on the drum by stopping the operation of the filterand, with a closed type filter removing the outer casing. The blade wasthen adjusted, by whatever means available, to what would appear to bethe proper pressure. The casing was then closed and the filter put backin operation. Such an adjustment of the scraper blade has been unsatisfactory not only because it has entailed a shutting down of thefilter in order to carry it out, but also it is very difficult to adjustthe blade to the proper pressure while the filter is not in operation.

Also, when the filter is being used with propane or other volatilesolvents it is necessary to stop operation of the filter, open it up andsteam it out for several hours before one can get inside to adjust theblade.

It is very important in the operation of rotary filters that theflexible scraper blade bear against the surface of the filter drum withjust sufficient pressure to remove the cake formed thereon. If the bladebears too hard against the surface, the wires which hold the cloth inplace on the drum will Wear the scraping edge of the blade, causingsharp edges which cut or damage the cloth.

An adjustable filter scraper blade embodying features of my invention isillustrated in the accompanying drawings forming a part of thisapplication, in which: r

Fig. l is a fragmentary front view, partly in section, taken along theline I-I of Fig. 2;

Fig. 2 is a view taken along line II--II of Fig. 1;

Fig. 3 is a view taken generally along the line III-III of Fig. 1;

Fig. 4 is a detail view IV-IV of Fig. 3; and

Fig. 5 is a detail view taken along the line V-V of Fig. 1.

Referring now to the drawings for a better understanding of my inventionI show a fragment of a rotary filter embodying a closed casing Hi and acylindrical drum II which may be provided with any suitable filteringmedium, such as cloth I? held in place by wires 13 wound spirally aboutthe drum. Also, the drum is provided with the usual partition walls I4forming a plurality of compartments.

The casing H] is provided with end Walls I5 and I8 and extending betweenand secured to the end walls as by welding at I! is a verticallyextending partition wall I8 which is spaced from the drum II, as shownin Fig. 2. Secured to the lower end of the wall l8 and to the inner walloi the casing I0 is a trough I 9 having rotatably mounted therein ascrew conveyor 2| for removing the material scraped from the drum ll.

Mounted on the wall [3 by any suitable means and extending substantiallythe length of the drum II, is an upwardly tapered bar 22. Secured to thebar 2?. by means of bolts 24 is a plate 26 which also extendssubstantially the length of the drum I I. While I show the bar 22 andthe plate 26 as being separate, they may, if desired, be formedintegrally.

Pivotally mounted at the top of the plate 25 by a hinge connection 27 isa scrap-er blade 28 which may be divided transverselyas at 25 to form aplurality of sections 28' which may be individually adjusted withrespect to each other. The over all length of the blade 28 is slightlygreater than the length of the drum H. The hinge connection 2? comprisesspaced sleeve members 23 and 3! which are secured to the top of theplate 26 as by welding or other suitable means. Secured to the undersideof the blade 23 and fitting between the spaced sleeve members 29 35 is ahinge member 3-3 which has a sleeve portion at fitting between thesleeves 29 and 35. Extending through the sleeves 29, 34 and 3! is ahinge pin 36, about which the scraper blade 2% thus free to rock.

Mounted on the underside of the blade 28 by any suitable means such asscrews 3'! are a plurality of leaf springs 38. The leaf springs arespaced longitudinally along the scraper 218 at taken along the line 4|extends outwardly of the outer casing [01 through a stufiing box $2 inthe end Wall I6. The stufiing box 42 is provided with a suitablepackinggland 43 to prevent leakage. outside of the casing 10. Adjustablymounted onthe. shaft M,

by any suitable means such as set screws 40,.op--

posite each of the leaf springs 38 is a crank arm. 44. Pivotally mountedat the free'end" of" each crank arm 44 is a push rod 46.

Mounted at the outer "end of each push rod 46 is ashort piece ofrod A!which extends parallel to theshaft 4|. Each rod 41 is disposed betweenits associated leaf spring 33v and the plate 26, whereby upon upwardmovement thereof the leaf spring 38 and the bottom of the. blade28 areurged. away from the plate 2.6. and the scraping edge of the blade isurged. towardthedrum H.

The outwardly projecting end of the shaft M is squared as at 4-3 and isprovided with anopeningAB for receiving. a suitable tool for turning it.

Keyed to the shaft M outwardly of the outercasing Hlis abracket 5!having a quadrant slot 52 therein. Mounted on the outer wall of thecasing. iii-adjacent the shaft 4| is anoutwardly projectin arm 53"havinga downwardly extending portion 54 adjacent the bracket 56, as shown inFig. 1. The downwardly extending portion-.54 is "provided with aninternally threaded open-.- ing56 opposite the s1ot52, for receiving. ascrew 57.. The screw til passes through the slot 52 and into the opening55 thus providing. means for. locking the shaft and blade assembly atany desired position.

Fromthe foregoing. description, the. operation of my adjustable-filtervscraper blade will bereadily understood. When the blade isinstalled aninitial. adjustment may be necessary. This ad-- I justment ismade. byloosening the set screws and adjusting the individual crank arms 44 soasto position the. entire scraping. edge of all-.the sections 28' of theblade against the drumv l I.

This. initial adjustment of the'bladeais veryim portant for. the reasonthatthe surfaceof long drums and the scraping edges of the-bladestherexfor are generally uneven, thus causing. uneven pressure, of theblade against thedrumz. By adjusting. the individual crank arms, allpoints along the entire length of the-blade-- bear with substantiallythe same pressure against the drum.

Filtersof the classhaving a closedcasing are usuallyprovided with peepholes 58 having pressure. tight glass covers 59 whereby'the-operationofithe: filter may be observed from the outside. m making-the finaladjustment of the blade, the

operatorlooks through one of the peep holes 58" in'the. casingand turnsthe-shaft 4| bya suit able tool at 48 or M3, as the case maybe, so as tocause the rods 45! to move downwardly toward: the lower end of thespring 38' thereby causingallsections 28 of the blade to be slacked offbetween. the leaf springsiiB and; the. plate 26. thus:

forcing the lower end of the leaf spring outwardly and causing thescraping edge of the blade 28 to bear against the drum ll withsuflicient pressure to remove the cake. The blade and shaft 4! are thenlooked in the adjusted positiomby; tightenin the screwfii.

While I have shown my. invention in" but one form, it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleof various changes and modifications without departing from the spiritthereof, and I desire, therefore; that onlw such limitations shall beplacedathereuponzaas are specifically set forth in thezappended-claims.

What Lclaim is:

1; The combination with a rotary filter embodyingza'. cylindrical filterdrum and a closed casing therefor, together with a scraper bladepiyotally. mounted! tobear. against said drum, ofZ'an-upwardlytapered;p1atev mounted inwardly of! said. blade,; aplurality, of:spaced: apart; lea-f. spring, memberseach. being; secured at oneend totheblade: along, the entire length. thereof',.the free ends of saidspring members; extending in a direction awayfrom the: scrapingedgezofrsaid blade intermediate the'blade and said plate, a movablemember for eaohspring member'inzposietion to slidably engage between.the free-,endaof its. associated springmember: and said platevandurgexthe scraping edge of. said. blade toward. said drum, a shaftextending through one? endiof: said. closed: casing. and operatively:connected. to each. of: said movable: members: for. moving the same, andmeans outwardly; of: said" casing: for; rotating said shaft."

2. Thecornbinationiv set:- forth; in? claimalin which the means forlocking:theshafttiniselecteed positions comprisesa bracket rigidlysecured to.-the shaft I outwardly of: the: closed: casing; a bracketsecured to": thefouter. wall; of. said: casing adjacent. saidv firstmentioned bracket" amine".-

' leasabla means: locking; said; brackets to: each other inselected-positions;

3: In a rotary drum filter-havingga -pivoted scraper. blade-,1 a;plurality-- of' leaf springs: dis:- posed. at intervalsunderneathqtherblade and: along the-length thereof, each. ofi said? springshaving'one'end' securedato the underside of: the blade and. the-other;extendingfreely at: aniangle. away from the blade; means-for adjusting.the: tension of. said springs: andthereby, thetpressureofv the. bladeagainstthe. drum: comprising-2am upwardly extendin member mounted,inwardly: of saidspringaa shaft: extending alongsiderthe". drumlongitudinallyfi'thereof; crankarmson the shaft, means fort-adjusting;the. individual crank; arms on the shaft thereby causingvtheyentiresblade to bearwith substantially uniform. pressureagainst the drum; andpush. rods; connected to. the crank. arms: with the-free ends: thereofslidably fittin between: said: upwardly extending, member and saidsprings.

4;.An adjustable scraper: for a: rotary. filter drum comprising an xupwardly eXtendingimem,- ber mounted:adjacent saidadrum; a scrapenbladepivotally mounted adjacent the toner said'smemiher and adapted? to bear"against: said .drum,. a: plurality of" spacedaapartl flexible; membersseecured to the blade alongthexlengthithereofanw having; their free endsextendingin a: direction: away from the scrapinged-ge of: said blade in"termediatessaid'bladeandsai'd'upwardly extend ing; member, a shaftrotatably mounted adjae cently below said upwardl'yr extendingmemher andextending parallel to said drum, crank arms adjustably mounted on saidshaft opposite each of said flexible members, push rods pivotallymounted to said crank arms with the free ends of each slidably fittingbetween its associated flexible member and said upwardly extendingmember and urging the scraping edge of said blade toward and away fromsaid drum upon rotation of said shaft in opposite directions.

5. The combination with a rotary filter drum having a scraper bladedivided transversely into a plurality of sections and pivotally mountedto bear against said drum, of an upwardly extending member mountedinwardly of said blade, a plurality of spaced apart flexible membersdisposed at intervals along the blade, each being secured at one end tothe blade and with a free end extending away from the scraping edge ofthe blade intermediate the blade and said upwardly extending member, anda movable mem her for each flexible member in position to slidablyengage between the free end of its associated flexible member and saidupwardly extending member and urge the scraping edge of said bladetoward said drum.

JOHN W. LITTLE.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,415,859 Bates May 16, 1922 FOREIGN PATENTS Number CountryDate 176,619 Great Britain Mar. 16", 1922

